The present invention relates to a transfer lever for a 4WD vehicle and, in particular, to an improved transfer lever adapted for use with transmissions of differing lengths.
Four wheel drive vehicles (4WD) include a transmission device in which the transfer is integrally attached to the transmission. The transfer includes a transfer lever which is operated to switch between 4 wheel drive and 2 wheel drive.
Referring to FIG. 7, a transmission device 102 of a 4WD automobile includes a transfer 106 attached at the rear of an automatic transmission (AT) 104-1. Because automatic transmission 104-1 includes parts such as torque converters or the like, it has a length A.
A transfer lever 108 in transfer 106 is operated to switch between 4 wheel drive and 2 wheel drive. Transfer lever 108 operates a 4-wheel 2-wheel switching mechanism (not shown). The distance between the attachment surface of transfer 106, where the rear surface of automatic transmission 104-1 is connected, and the center 110C of a lever attachment piece 110, where the base end of transfer lever 108 is attached, is identified as B. Furthermore, a knob attachment piece 112 at the tip of transfer lever 108 is positioned to the rear of center 110C.
Referring to FIG. 8, there is shown a prior-art transmission device 102 having a manual transmission (MT) 104-2. Transfer 106 is attached to manual transmission 104-2 in the same manner as with automatic transmission 104-1.
Manual transmission 104-2 does not require parts such as torque converters, or the like. As a result, it has a length C which is slightly less than length A of automatic transmission 104-1. This difference in length positions transfer lever 108 knob attachment piece 112 to the rear of center 110C.
An example of this transfer device for a 4WD automobile is disclosed in Japanese Laid Open Patent number 8-156625. In this publication, a transfer is connected to a transmission. In this transfer, there are 3 shift positions: a high speed gear on demand 4 wheel drive position, in which the safety of on road driving is improved; a high speed gear direct 4 wheel drive position, which is suited for continuous off road driving; and a low speed gear direct four wheel drive position, which is suited for situations where a large drive torque is necessary in off-road driving. With this transfer, it is possible to easily switch between the three shift positions with one switching rail which interlocks with the transfer lever. On-road safety and off-road driveability can coexist.
However, referring to FIG. 9, when attaching transfer 106, which has the same length B to each of automatic transmission 104-1, which has a longer length A, and manual transmission 104-2, which has a shorter length C, the position at which transfer lever 108 is located is changed. The change is by a measurable distance D between the location of center 110C of lever attachment 110 of automatic transmission 104-1 and center 110C of lever attachment 110 of manual transmission 104-2. Furthermore, the position of knob attachment piece 112 of transfer lever 108 also changes in the front to rear direction. As a result, the optimal shift position is not achieved in both manual and automatic transmissions. Furthermore, when there is a difference in the length of the transmission, one single transfer lever can not accommodate differing types of vehicles.